and the rivers of the sub-continent must be
aided by an examination of the map which has been specially prepared
in order to make the description intelligible.

[Sidenote: General aspect of area.]

The tableland of South Africa is some 1,360,000 square miles in
extent, and of a mean altitude of 3,000 to 5,000 feet above sea level.
To the Indian Ocean on the east it shows a face of scarped mountains.
Following the coast-line at a distance inland of from 70 to 100
miles, these sweep round from north to south: then stretch straight
across the extreme south-west of the continent through Cape Colony,
dwindling as they once more turn northward into the sand-hills of
Namaqualand, and rising again to the eminences above Mossamedes in
Portuguese territory. The rampart, however, though continuous for a
distance of more than 1,200 miles, scarcely anywhere presents an
abrupt wall to the seaboard, but on the contrary descends to it in
some parts in one gigantic step, in others in a series of steps, or
terraces.

[Sidenote: Cape Colony: the Karroos.]

Of the States within it, Cape Colony first claims consideration. In
the central section the step or terrace formation is so marked, and
the flats, which intervene between the rises, are of such extent, and
of a nature so curious, that they form one of the most remarkable
features of South Africa. They are known as "the Karroos," vast plains
stretching northward, firstly as the Little Karroo from the lower
coast ranges to the more elevated Zwarte Bergen, thence as the Great
Karroo to the still loftier Nieuwveld Mountains. In the rainless
season they present an aspect indescribably desolate, and at the same
time a formidable military obstacle to any invasion of Cape Colony on
a large scale from the north. They are then mere wastes of sand and
dead scrub, lifeless and waterless. The first fall of rain produces a
transformation as rapid as any effected by nature. The vegetable life
of the Karroos, which has only been suspended, not extinguished, is
then released; the arid watercourses are filled in a few hours, and
the great desert tract becomes within that brief time a garden of
flowers. Even then, from the scarcity of buildings and inhabitants,
and hence of supplies, the Karroos still form a barrier not to be
lightly attempted, unless by an army fully equipped, and carrying its
own magazines; or, on the other hand, by a band of partisans so
insignificant as to be able to subsist on t